harmine and Adenocarcinoma

The beta-carboline alkaloids are naturally existing plant substances. It is known that these alkaloids have a wide spectrum of neuropharmacological, psychopharmacological, and antitumor effects. Therefore, they have been traditionally used in oriental medicine for the treatment of various diseases including cancers and malaria. In this study, harmol and harmalol, which are beta-carboline alkaloids, were examined for their antitumor effect on human lung carcinoma cell lines, and structure-activity relationship was also investigated. H596, H226, and A549 cells were treated with harmol and harmalol, respectively. Apoptosis was induced by harmol only in H596 cells. In contrast, harmalol had negligible cytotoxicity in three cell lines. Harmol induced caspase-3, caspase-8, and caspase-9 activities and caspase-3 activities accompanied by cleavage of poly-(ADP-ribose)-polymerase. Furthermore, harmol treatment decreased the native Bid protein, and induced the release of cytochrome c from mitochondria to cytosol. The apoptosis induced by harmol was completely inhibited by caspase-8 inhibitor and partially inhibited by caspase-9 inhibitor. The antagonistic antibody ZB4 blocked Fas ligand-induced apoptosis, but had no effect on harmol-induced apoptosis. Harmol had no significant effect on the expression of Fas. In conclusion, our results showed that the harmol could cause apoptosis-inducing effects in human lung H596 cells through caspase-8-dependent pathway but independent of Fas/Fas ligand interaction.

Topics: Adenocarcinoma; Apoptosis; Carcinoma, Adenosquamous; Carcinoma, Non-Small-Cell Lung; Carcinoma, Squamous Cell; Caspase 3; Caspase 8; Caspase 9; Cell Line, Tumor; Enzyme Activation; Fas Ligand Protein; fas Receptor; Harmaline; Harmine; Humans; Lung Neoplasms; Neoplasm Proteins

A novel mutagenic compound, 9-(4'-aminophenyl)-9H- pyrido[3,4-b]indole (aminophenylnorharman, APNH), is shown to be formed by the in vitro enzymatic reaction of 9H-pyrido[3,4-b]indole (norharman) and aniline. APNH generates DNA adducts (dG-C8-APNH), and is potently genotoxic to bacteria and mammalian cells. APNH has also been demonstrated to be formed in vivo from norharman and aniline, and suggested to be a new type of endogenous mutagenic compound. To determine its carcinogenic activity, long-term administration of APNH was investigated in 93 male and 90 female F344 rats. Rats were fed diets containing 0, 20 or 40 p.p.m. from 7 weeks of age. All animals were killed after 85 weeks treatment and necropsy was performed. Hepatocellular carcinomas (HCCs) were induced at incidences of 10 and 79% in male rats fed 20 and 40 p.p.m. APNH, and 34% in female rats fed 40 p.p.m. of APNH, respectively. In addition, colon adenocarcinomas were found at incidences of 3 and 9% in male rats, and 4 and 13% in female rats fed 20 and 40 p.p.m. of APNH, respectively. Other tumors, including thyroid carcinomas and mononuclear cell leukemia, were also seen in rats fed APNH. Polymerase chain reaction-single strand conformation polymorphism analysis revealed beta-catenin gene mutations in 24% of HCCs and K-ras, beta-catenin and Apc gene mutations were found in 22, 44 and 33% of colon cancers induced by APNH, respectively. Most mutations occurred at G:C base pairs. beta-Catenin protein accumulations in the nucleus and cytoplasm were also revealed in both liver and colon tumors. Thus, APNH induced liver and colon cancers with K-ras, beta-catenin and Apc gene mutations in F344 rats.

Topics: Adenocarcinoma; Aniline Compounds; Animals; beta Catenin; Carbolines; Carcinoma, Hepatocellular; Colon; Colonic Neoplasms; Cytoskeletal Proteins; Female; Genes, APC; Genes, ras; Harmine; Indoles; Leukemia; Liver; Liver Neoplasms; Male; Mutagens; Mutation; Polymerase Chain Reaction; Polymorphism, Single-Stranded Conformational; Pyridines; Rats; Rats, Inbred F344; Thyroid Neoplasms; Trans-Activators